Patients who are bedridden for appreciable periods of time often develop persistent and painful bedsores .differential.decubitus ulcers[. It is generally believed that the bedsores are produced by relatively high pressures exerted upon the body by a conventional mattress in body regions where these regions engage the mattress. In order to inhibit the development of bed sores, it is known that certain types of air filled mattress, designed to minimize these pressures, can be disposed on top of the conventional mattress so that the patient lies on top of the air filled mattress and the body regions engage the air filled mattress and are subject to relatively low pressures rather than engaging the conventional mattress and being subject to the relatively high pressures.
However, as a nurse moves or shifts the patient in position, the air filled mattress is also moved in relationship relative to the conventional mattress on which the patient rests. This movement is always undesirable, but can also be sufficiently large to cause the patient to slip off the air mattress or to cause both the patient and the air mattress to slip off the conventional mattress.
The present invention is directed toward a new type of air filled mattress construction which enables the air mattress to be firmly secured to the conventional mattress in such manner that the air mattress cannot be moved in position relative to the conventional mattress on which it rests, regardless of any patient movement or shift in position.